This invention relates generally to an apparatus for making tubular objects from a strip of material. More particularly, the invention relates to an apparatus which produces helically wound tubes or pipes of varying sizes from, preferably a continuous strip of material.
Machines for helically winding strips of material into a pipe, tube, or other form of tubular objects are known. These machines typically receive a strip of material, e.g. a continuous strip, bend that material into a loop, and concurrently connect the newly formed loop onto an edge of an incoming portion of the strip. This process results in a helically wound tubular object which, depending upon the material of the strip, is suitable for a variety of uses. Tubular objects formed in this way are currently used as conduits, sewage pipes, or reels, just to name a few.
These machines usually include a circular rolling surface which receives the material and bends it into a loop. This rolling surface can comprise of a circular arrangement of rollers or a circular metallic band. The rollers or metallic band defines the radius of the formed tubular object.
The strip is typically fed into a machine along a bottom portion of the rolling surface and travels along the rolling surface to form a loop. As additional portions of the strip are fed into the roller assembly, an edge of the newly formed loop is guided to overlap an incoming strip portion along an edge. The overlapping edges are then connected so that the formed loop is eventually completely connected to an incoming portion of the strip.
The formed loops attach to the incoming strip portion in many ways. Some apparatus apply layers of adhesive along the edges of a strip and apply pressure along overlapping edges to adjoin the two. In more heavy duty applications, the strip is formed of a flexible plastic material having connecting structures incorporated along its edges. In these cases, the engaging structures on overlapping portions sealingly engage each other to sealingly connect the overlapping portions.
While the prior art is currently capable of making tubular objects from a continuous strip of materials, most of the prior art references are only capable of making tubular objects of one size. In many instances, tubular objects of different diameters are required and so the prior art necessitates either the use of only one size pipe for all applications or the use of multiple machines.
In many cases, the tubular objects produced are heavy duty pipes that provide a pathway for fluids or carry cables, and other structures. Often, newly wound pipes are directly inserted within preexisting underground piping or tunnels as they are formed. The appropriate diameter pipe is typically dependant upon the job site.
However, a new pipe forming machine is typically needed whenever a pipe of a different size is needed. The expediency of setting up and carrying just one machine for a given job, or the cost of additional pipe forming machines often prevent the use of multiple machines. As a result, the ideal diameter of pipe for a given site may not be used.
Consequently, there is a need for a pipe forming apparatus which is capable of being easily adjusted to create pipes of varying diameters from readily available strip material.
The present invention is an apparatus for making tubular objects of various diameters from a strip of material such as a continuous strip material. The present invention includes a unique circular rolling surface which is radially adjustable so that the apparatus is able to form tubular objects of different diameter.
In one embodiment, the subject invention includes a frame comprising of corresponding front and rear plates coaxially mounted to each other by a plurality of spacers. Each plate includes an aperture extending therethrough, the apertures overlaying each other to define a generally circular passage which extends through the frame. A plurality of slots extend through each plate, with each slot extending in a direction that is generally radial to the aperture.
A generally circular pathway is incorporated into the frame to receive and bend the strip of material as it passes through the subject invention. In one embodiment, the circular pathway is a rolling surface formed by a plurality of rollers disposed within the passage. The rollers are in a generally circular arrangement, circumferentially positioned about the passage.
In one embodiment, the rollers are suspended within the passage by an adjustable arm which is mounted to the frame on one end, and is rotatably coupled to a roller on an opposite end. Adjustable arms are correspondingly positioned between both plates so that the arms on one plate are aligned to the arms located on the opposing plate, thus allowing a roller to be rotatably coupled on both ends by an arm.
In one embodiment, the adjustable arm includes a threaded rod that is rotatably mounted to a plate or by a mounting plate. The rod includes a head portion and a threaded portion. The adjustable arm also includes an extension which engages a rod and a slot. A first end of the extension includes a flange shaped to engage a slot and a threaded ring to threadedly engage the threaded portion of the rod. A second end of the extension includes a coupling means for rotatably engaging the roller.
The diameter of a formed pipe can be changed by engaging the head portion of the rod and rotating the rod about its axis. The revolution of the rod causes the extension to travel longitudinally on the rod, this driven by the relative displacement of the threaded ring with respect to the threaded portion of the rod. This causes a radial movement of a roller relative to the passage. The rollers are individually adjusted until a desired diameter of pipe are produced.
While several embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following figures and detailed description. As will be realized, the invention is capable of modifications in various obvious aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.